A tank contains 100 gal of brine made by dissolving 60 lb of salt in water. Salt water containing 1 lb of slat per gallon runs in at the rate of 2 gal/min and the well stirred mixture runs out at the same rate of 3 gal/min. Find the amount of salt in the tank after 30 minutes.

Question

A tank contains 100 gal of brine made by dissolving 60 lb of salt in water.  Salt water containing 1 lb of slat per gallon runs in at the rate of 2 gal/min and the well stirred mixture runs out at the same rate of 3 gal/min.  Find the amount of salt in the tank after 30 minutes.

anonymous · Answer

y'=2-(3y/100)
solve this differential eqn to get amount of salt(y) as a function of time.
then find y(30)

anonymous · Answer

Alright, hope it works :S

anonymous · Answer

I solved it and I get y(x)=Ce^(-3x/100) + 200/3